My Startup Items Mysteriously Changed

When I started my G4 this morning my StartUp items had changed. My iCal startup item had been replaced by a .jpg file (which launched the Viewer). The .jpg image was a web button with japanese (I think) writing on it.

Did some internet "spyware" or similar program do this? Is there any other way this could have happened??

If u want to see if there is spyware runing on your computer, fire up good 'ol process viewer, and look for something out of place. I too have had spyware infect my computer and run a window at startup with a URL in it or some such. get rid of it asap.